Product manual

Preliminary CompactFlash Memory Card Product Manual

Changed Indicates that one or both of the Pin Replacement register CRdy, or CWProt bits are set to one (1). When the

Changed bit is set, -STSCHG Pin 46 is held low if the SigChg bit is a One (1) and the CompactFlash

Memory Card is configured for the I/O interface.

SigChg This bit is set and reset by the host to enable and disable a state-change “signal” from the Status Register, the

Changed bit control pin 46 the Changed Status signal. If no state change signal is desired, this bit should be

set to zero (0) and pin 46 (-STSCHG) signal will be held high while the CompactFlash Memory Card is

configured for I/O.

IOis8 The host sets this bit to a one (1) if the CompactFlash Memory Card is to be configured in an 8 bit I/O mode.

The CompactFlash Card is always configured for both 8- and 16-bit I/O, so this bit is ignored.

PwrDwn This bit indicates whether the host requests the CompactFlash Memory Card to be in the power saving or

active mode. When the bit is one (1), the CompactFlash Card enters a power down mode. When zero (0), the

host is requesting the CompactFlash Card to enter the active mode. The PCMCIA Rdy/-Bsy value becomes

BUSY when this bit is changed. Rdy/-Bsy will not become Ready until the power state requested has been

entered. The CompactFlash Card automatically powers down when it is idle and powers back up when it

receives a command.

Int This bit represents the internal state of the interrupt request. This value is available whether or not I/O

interface has been configured. This signal remains true until the condition which caused the interrupt request

has been serviced. If interrupts are disabled by the -IEN bit in the Device Control Register, this bit is a zero

(0).

4.4.4 Pin Replacement Register (Address 204h in

Attribute Memory)

Operation D7 D6 D5 D4 D3 D2 D1 D0

Read 0 0 CRdy/-Bsy CWProt 1 1 RRdy/-Bsy RWProt

Write 0 0 CRdy/-Bsy CWProt 0 0 MRdy/-Bsy MWProt

CRdy/-Bsy This bit is set to one (1) when the bit RRdy/-Bsy changes state. This bit can also be written by the host.

CWProt This bit is set to one (1) when the RWprot changes state. This bit may also be written by the host.

RRdy/-Bsy This bit is used to determine the internal state of the Rdy/-Bsy signal. This bit may be used to determine the

state of the Ready/-Busy as this pin has been reallocated for use as Interrupt Request on an I/O card. When

written, this bit acts as a mask for writing the corresponding bit CRdy/-Bsy.

RWProt This bit is always zero (0) since the CompactFlash Memory Card does not have a Write Protect switch.

When written, this bit acts as a mask for writing the corresponding bit CWProt.

MRdy/-Bsy This bit acts as a mask for writing the corresponding bit CRdy/-Bsy.

MWProt This bit when written acts as a mask for writing the corresponding bit CWProt.